Ladle feeding means



Oct. 16, 1962 H. E. STENZEL LADLE FEEDING MEANS 2 Sheets-Sheet 1 FiledSept. 14. 1959 INVENTOR H%erbert E. Stenzel Oct. 16, 1962 H. E. STENZEL3,058,621 LADLE FEEDING MEANS Filed Sept. 14. 1959 Fig.3.

2 Sheets-Sheet 2 INVENTOR Herbert E. Stenzel WW7 3,058,621 LADLE FEEDINGlv IEANS Herbert E. Stenzel, Hampton Township, Allegheny County, Pa.,assignor to Blaw-Knox Company, Pittsburgh, Pa., a corporation ofDelaware Filed Sept. 14, 1959, Ser. No. 839,886 6 Claims. (Cl. 222-58)This invention relates to the feeding of addition materials to a ladleof molten metal for alloying material into the molten bath and isparticularly useful in supplying addition material at a controlled rateduring tapping of a furnace.

In the manufacture of metals it is the usual practice to make alloys inwhich a number of metals are combined. The most notable example isprobably in the steel industry. The manufacture of pure iron isextremely rare and commercial practice is directed to the manufacture ofvarious steel alloys. In practice, steel is commonly' refined in afurnace, such as an open hearth furnace or an electric furnace, in whichimpurities are reduced and alloying constituents added. It is customaryto make an analysis of the molten steel shortly before tapping thefurnace and then to add whatever alloying constituents are necessary.Many such constituents are added to the furnace shortly before tapping.It is, however, common practice to add some alloying materials to theladle into which the molten metal is tapped while tapping actually takesplace. This practice avoids loss of alloying ingredients in the furnaceand, if the alloying ingredients are added continuously during tapping,results in their even distribution throughout the ladle.

I provide an addition material supply hopper having an outlet in thelower portion thereof, material receiving means movable between a firstposition in which material flowing from the outlet accumulates on thematerial receiving means and a second position in which the materialdischarges therefrom by gravity forraddition into the ladle. Ipreferably provide trough means placed beneath the addition materialoutlet and having a first position in which the edges of the troughmeans extends beyond the confines of the angle of repose of materialdischarging from said outlet onto the trough means and a second positionin which the angle of repose of said material extends beyond at leastone edge of said trough means. I preferably provide vibratory meansadjacent said trough means and selectively operable to dischargematerial from said trough means when it is in said first position. Ifurther preferably provide electric load measuring means supporting thesupply hopper and combine said means in an electric circuit with presetswitch means whereby said vibratory means is selectively operable tocause discharge of addition material from said trough means until theload is reduced to a predetermined level. I further preferably providemeans for shifting said trough means between the first position and thesecond position. I prefer to provide a plurality of hoppers and feedingmeans discharging into the common chute means for delivery of aplurality of addition materials selectively and simultaneously from aplurality of hoppers into a ladle.

Other details, objects and advantages of my invention will become moreapparent as the following description of a present preferred embodimentthereof proceeds.

In the accompanying drawings I have illustrated a present preferredembodiment of my invention in which FIGURE 1 is a side view of anaddition material feeding installation embodying my invention;

FIGURE 2 is an end view of the apparatus shown in FIGURE 1;

FIGURE 3 is a view of the apparatus shown in FIG- URE l with the feedersshown in manual dumping position; and

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FIGURE 4 is a diagrammatic view of the control circuit for one of thevibratory feeders shown in FIGURE 1. A storage hopper 1 which maycontain ferromanganese 1s provided for use in the manufacture of steel.A similar hopper 1a is provided for storage of ferrosilicon. All of thecorresponding members associated with each of the hoppers aresubstantially alike and they are referred to by like numbers throughout.Each hopper has a lower tapering portion 2 terminating in an outlet 3 atthe lower portion thereof. A plate 4 is attached to the upper portion ofeach hopper 1 and 1a and has an opening 5 formed therein to receive acrane hook. Each hopper is supported by a plurality of generallytriangular shaped plate-like members 6 which are welded in right angularrelationship to each other beneath the four corners of each hopper. Thepair of members 6 at each corner of the hopper narrows toward the lowerend and terminates at a pad 7 welded beneath each pair of plate-likemembers 6 at each hopper corner. The supporting structure formed bymembers 6 are set within the confines of four vertical angular shapedstructural members 8 which are set in the mill floor. A shelf 9 isplaced in the inside corner of each structural member 8 and is braced bya member 10. An electric load measuring device 11 such as an SR-4 loadcell, manufactured by Baldwin-Lima- I-Iamilton Corporation, is placed oneach shelf 9. Such load cells comprise a body element supporting theload which is thereby strained in proportion to the applied load and afilamentary member bonded to the body element. The strains in the bodyelement are proportionally transmitted to the filamentary member. Theresistance of the filamentary member thus changes in known relationshipto the applied load. By making measurements of the resistance of thefilamentary member the amount of the applied load and changes thereinmay be determined. One example form of load cell of these generalcharacteristics is shown in Ruge Patent 2,488,348.

T 0 center the hoppers within the supporting structure to rest on theload cells without vertical restraint, struts 15 are secured across themember 6 on all four sides, and at the center of each strut is secured avertical member 16 of channel shaped cross section extending downwardlysubstantially to the level of the pads 7. Flat flexible bars 12 extendbetween the supporting frame uprights 8 parallel to the struts 15, andare connected at their centers to the vertical member 16. Flexible tierods 13 and 17 also extend horizontally from the flanges of the channels16 to brackets 14 on the supporting frame, the tie rods having threadedends with nuts thereon for adjusting their length and centering thehopper within the frame. It will be seen that the weight of each hopperis carried by load cells 11 and that the hopper is free to movevertically but that horizontal movement is restricted by tie rods 17,and tie rods 13.

A pair of feeder supporting frames 18 are mounted for pivotal movementon a shaft 19 extending through the lower portion of each hopper. Ashaft 20 extends between frames 18 at one end and a shaft 21 extendsbetween frames 18 at their opposite ends. A plurality of links 22 arepivotally suspended from each of frames 18 near each end and carry awell-known type of vibratory feeder. A vibratory feeder of the type madeby Syntron Company, may conveniently be used. Each feeder comprises atrough 23 having raised edges 24 which are open at one end to form adischarge at 25. A vibrator 26 is connected to the trough and issupplied from a power cable 27. When vibrator 26 is energized it impartsan uneven vibratory motion to the trough which has the effect ofdisplacing the trough relative to the material in it by rapidly shiftingthe trough in one direction and then returning it at a more moderatespeed. The result is to move the material in the trough in smallincrements,

eventually discharging it from the trough at 25. The trough is supportedclose to the outlet so that the edges of the trough, including the edgeat discharge 25 all extend beyond the limits of a pile deposited on thetrough from the adjacent hopper when the trough is in the position shownin FIGURE 1. Stated in other terms, the edges of the trough when it isin that position extend beyond and intersect the angle of repose ofmaterial flowing from the outlet into the trough.

When frames 18 are in the position shown in FIGURE 1, shaft 20 bearsagainst lower hopper section 2. Rotation of frames 18 to move shaft 20away from the hopper will bring shaft 21 against the lower hopperportion 2, at which time the trough will be in an inclined position asshown in FIGURE 3. When the trough is inclined as shown in FIGURE 3, theedges of the trough no longer cut off How of material, and it will slidedown the in clined surface of the trough.

A double acting fluid power cylinder 28 is pivotally mounted to thesupporting framework on each hopper at 29. The piston rod is connectedto bracket 39 on the frame 18. The cylinder is powered in theconventional manner from a compressed air supply which has been omittedfrom the drawings for the purpose of clarity.

A gate 31 is pivoted from each hopper at 32 and may be lowered into thetrough to close discharge while the hopper is being filled. The free endof gate 31 is connected to a cable 33 extending over pulleys 34 andhaving at its free end a hand ring 35. Gate 31 may be raised or loweredby pulling on the ring 35.

A chute 36 is placed beneath each trough 23 in position to receivematerial discharged at 25. The chute terminates above a ladle 37 whichis shown in tapping position.

An auxiliary addition material hopper 38 is mounted on the framework38:: and discharges through a funnel 40 into chute 36. Hopper 38 isopened and closed by a bell 41 which is movable up and down to close theopening.

FIGURE 4 diagrammatically shows the vibrator control circuit for one ofthe hoppers. Power is supplied on lines 42 and 43. A line switch 44 isprovided for both lines. A primary winding 45 of a stepdown transformeris connected across lines 42 and 43. The secondary winding 46 isconnected through a normally closed push button switch 47 and normallyopen push button switch 48 to a relay 49 and then through a normallyclosed switch 59 operated by relay 51 from which the circuit iscompleted to the other side of secondary winding 46. Switch 47 isdesignated as a stop switch and switch 48 is designated as a startswitch. A circuit 52 bypasses switch 48 through normally open switch 53which is closed by operation of relay 49.

A circuit 54 extends from power line 42 through normally open switch 55,which is controlled by relay 49, then through rectifier 56 and variableresistor 57 to the coil 58 of the feeder and then through normally openswitch 59, which is also controlled by relay 49, to power line 43.

A controller, indicated at 60, is provided for each hopper. Itselectively energizes relay 51 through wire 61. The controller receivesan electrical signal through wire 62 from load cells 11 which isproportional to the load upon the load cells. The signal is amplified bythe controller and produces a corresponding movement of an indicatingarm 63 which points to an indicator dial 64 visually showing loadcarried by the load cells. A correction for tare weight may be includedin controller so that the indicated reading will show the amount ofmaterial actually in each hopper. An electrical contact point 65 isdiagrammatically shown on pointer 63. A second pointer 66 is manuallyset. It also carries an electrical contact point indicated at 67. Whenactual measured load, as shown by pointer 63, is reduced to the figureat which pointer 66 is set, contacts 65 and 67 complete an electricalcircuit within the controller which causes the controller to momentarilyenergize relay 51.

In the use of the invention hoppers 1 and 1a are filled withferromanganese and ferrosilicon, respectively, at convenient intervals.They may, for example, be filled on a daily schedule at a time which isconvenient in the mill. When a heat is about to be tapped into ladle 37an analysis of the heat is made. The amount of ferrosilicon andferromanganese which is to be added to the ladle during tapping is thencalculated. The reading for each hopper, as shown by the associatedpointer 63, is noted and pointer 66 is then set at a smaller figure sothat the difference between the two readings is equal to the amount ofmaterial to be discharged into the ladle. The associated resistor 57 isadjusted to operate the feeder at a speed which will feed the properamount of addition material during tapping to the extent desired by theoperator. For example, if the amount to be added is small, a reducedrate of feed may be set to add material throughout the time tappingtakes place.

When the furnace is initially tapped the operator momentarily pushes thestart button closing switch 48 and energizing relay 49. Relay 49 thencloses switches 53, 55, and 59, thereby holding itself energized throughcircuit 52 and connecting the vibratory feeder across the line. Thevibrator then produces an uneven vibration of trough 23 causing a rapidmovement of the trough in one direction and a relatively slow returnmovement. This will advance material in the trough over discharge 25 ina well-known fashion. When the load has been reduced to the presetamount contacts 65 and 67 will come together completing a circuit andcausing controller 69 to momentarily de-energize relay 51, therebyopening switch 50 and breaking the circuit for relay 49. This in turnwill result in opening switches 53, 55, and 59. Operation of thevibrator will then cease and no further discharge will occur.

In the event of malfunctioning of the feeder or an electrical failure,cylinder 28 is energized from a source of compressed air to shift thetrough to the position shown in FIGURE 3. The material will then flowfrom the hopper by gravity across the trough and onto chute 36 fromwhich point it will then flow into the ladle. When the proper amount ofmaterial has been provided as indicated by a change in the reading ofpointer 63 the operator supplies compressed air to cylinder 28 to returnthe feeder to horizontal position.

Gates 31 are lowered during filling of the hoppers to prevent accidentaldischarge due to momentum of material being loaded into the emptyhopper.

While I have illustrated and described a present preferred embodiment ofmy invention it is to be understood that I do not so limit myself andthat my invention may be otherwise variously practiced within the scopeof the following claims.

I claim:

1. Ladle addition means comprising an addition material supply hopperhaving an outlet in the lower portion thereof, electric load measuringmeans supporting said hopper, material receiving means positionedbeneath said outlet and extending beyond the limits of a pile formed bydischarging material from said outlet onto said material receivingmeans, said material receiving means having electrically operable meansassociated therewith to discharge material therefrom, electric circuitmeans including said load measuring means and preset control means incontrolling relationship to said electrically operable means wherebyoperation of said electrically operable means is stopped when the loadmeasured by said load measuring means is reduced to a preset amount.

2. Ladle addition means comprising an addition material supply hopperhaving an outlet in its lower portion, electric load measuring meanssupporting said hopper, material receiving and feeding means mountedbeneath said hopper and effective in one position to feed materialflowing from the outlet, electric circuit means including said loadmeasuring means, and switch means responsive to the load measured bysaid measuring means and controlling said material receiving meanswhereby said ma terial receiving means are maintained effective to feedmaterial until the measured load is reduced to a preset value.

3. Ladle addition means comprising an addition material supply hopperhaving an outlet in its lower portion for gravity discharge of additionmaterial therefrom, a supporting frame for said hopper resting onelectric load measuring means, material receiving and feeding meanspositioned beneath said outlet, drive means for said receiving andfeeding means, and electric circuit means controlling said drive meansand including said load measuring means and associated switch meansadjustably preset to operate when the measured load equals said presetamount whereby said drive means feeds material until the measured loadis reduced to said preset value.

4. Ladle addition means comprising an addition material supply hopperhaving an outlet in its lower portion for gravity discharge of additionmaterial therefrom, a supporting frame for said hopper resting onelectric load measuring means, material receiving and feeding meanspositioned beneath said outlet, drive means for said receiving andfeeding means, electric circuit means controlling said drive means andincluding said load measuring means and associated switch meansadjustably preset to operate when the measured load equals said presetamount whereby said drive means operates the receiving and feeding meansto feed material until the measured load is reduced to said preset Valueand then operates the receiving and feeding means to stop feedingmaterial, and selectively operable switch means controllingcornmencement of operation of said drive means.

5. Ladle addition means comprising an addition material supply hopperhaving an outlet in its lower portion for gravity discharge of additionmaterial therefrom, a supporting frame for said hopper resting onelectric load measuring means, material receiving and feeding meanspositioned beneath said outlet and movable between a first position inwhich addition material accumulates on said means and a second positionin which addition material discharges from said means by gravity, drivemeans associated with said means and operable to feed addition materialfrom said means in said first posi ion when said drive means areactivated, adjustable switch means in controlling relationship to saiddrive means, said switch means being in electric circuit with said loadmeasuring means and adjustable to open the drive means circuit when themeasured load falls below a predetermined amount whereby the switchmeans is adjustable to feed a preset weight of addition material,

6. Ladle addition means comprising a plurality of addition materialsupply hoppers, each hopper having an outlet in its lower portion forgravity discharge of addition material therefrom, a hopper supportingframe supporting each hopper and carried by electric load measuringmeans, material receiving and feeding means positioned beneath saidoutlet and movable between a first position in which addition materialdischarging from said outlet accumulates on said receiving and feedingmeans and a second position in which said material discharges therefromby gravity, drive means associated with said receiving and feeding meansand operable to discharge material from said receiving and feeding meanswhen in said first position, power means in operative relationship withsaid receiving and feeding means and operable to shift said meansbetween said first position and said second position, switch meansoperable to begin operation of said drive means, and preset switch meansconnected with said load measuring means and operable to open thecircuit of said drive means whereby operation of said drive means isstopped when the measured load is reduced to a preset amount.

References Cited in the file of this patent UNITED STATES PATENTS2,100,878 Shallock Nov. 1937 2,303,633 Elliott Nov. 24, 1942 2,319,795Cofiin May 25, 1943 2,544,155 Harkenrider Mar. 6, 1951 2,568,332Genovese Sept. 18, 1951 2,638,244 Alvord May 12, 1953 2,921,713 Zanottoet a1. Ian. 19, 1960 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3,058,621 October 16, 1962 Herbert E. Stenzel Itis hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 6, line 42, under "References Cited" for "2.638244" read 2,638248 Signed and sealed this 5th dhy of March 1963.

(SEAL) Attest:

DAVID L. LADD Commissioner of Patents ESTON G. JOHNSON Attesting OfficerDisclaimer 3,058,621.He1-be7't E. Stewed, Hampton Township, AlleghenyCounty, Pa. LADLE FEEDING MEANS. Patent dated. Oct. 16, 1962. Disclaimerfiled J an. 22, 1964, by the assignee, Elmo-Know Company. Hereby entersthis disclaimer to claims 16 inclusive of said patent.

[Ofioz'al Gazette April .74, 1.964.]

